As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
TYS A/C WAS EN ROUTE TO SDF WHEN THE CREW SAW SOME SMOKE IN THE CABIN FOR A FEW MINUTES. CONTINUED ON TO SDF. MAINTENANCE REPLACED THE NR 1 ENGINE IAW TASKCARD 1271001. OPS AND LEAK CHECKS WERE GOOD. A/C WAS PUT BACK IN SERVICE. REFERENCE LOG PAGE 2149208. [07-27-07] SMOKE WAS CAUSED BY THE NR 4 CARBON SEAL LEAKING.